The Historical Changes in Japanese Language Teaching for Brazilian-Japanese in Brazil : Results from Questionnaires to Brazilian-Japanese Who Experienced Learning Japanese <Articles>

This study focuses on the changes in educational concept for the descendent generations of immigrants. Until now, changes to educational concepts in Japanese language teaching to Brazilian-Japanese have only been observed through the perspective of the educators. The purpose of this study is to clarify these changes through the perspectives of two sides: That of the educators, and that of the learners, who accepted these changes. Japanese-language teaching in Brazil has been changed by Japanese immigrants in past 100 years. At First, it was changed from education for young Japanese immigrants to heritage language teaching for Brazilian-Japanese after World War II. Secondly, the teaching concept was changed from Japanese teaching as a heritage language to Japanese teaching as a foreign language. Research results show that Brazilian-Japanese who experienced learning Japanese prior to the changes were hoping for the same changes mentioned in the two stages above. This study clarified that Brazilian-Japanese in Brazil also had the awareness of the issues on the educator's side before the changes of educational concepts. At the present time, many Brazilian-Japanese live with their families in Japan. They also have the same problems about learning language as their former generations

Reconstruction of the 2014 eruption sequence of Ontake Volcano from recorded images and interviews

A phreatic eruption at Mount Ontake (3067 m) on September 27, 2014, led to 64 casualties, including missing people. In this paper, we clarify the eruption sequence of the 2014 eruption from recorded images (photographs and videos obtained by climbers) and interviews with mountain guides and workers in mountain huts. The onset of eruption was sudden, without any clear precursory surface phenomena (such as ground rumbling or strong smell of sulfide). Our data indicate that the eruption sequence can be divided into three phases. Phase 1: The eruption started with dry pyroclastic density currents (PDCs) caused by ash column collapse. The PDCs flowed down 2.5 km SW and 2 km NW from the craters. In addition, PDCs moved horizontally by approximately 1.5 km toward N and E beyond summit ridges. The temperature of PDCs at the summit area partially exceeded 100 °C, and an analysis of interview results suggested that the temperature of PDCs was mostly in the range of 30–100 °C. At the summit area, there were violent falling ballistic rocks. Phase 2: When the outflow of PDCs stopped, the altitude of the eruption column increased; tephra with muddy rain started to fall; and ambient air temperature decreased. Falling ballistic rocks were almost absent during this phase. Phase 3: Finally, muddy hot water flowed out from the craters. These models reconstructed from observations are consistent with the phreatic eruption models and typical eruption sequences recorded at similar volcanoes.ArticleEarth, Planets and Space. 68:79 (2016)journal articl

Prohibitin 2 regulates the proliferation and lineage-specific differentiation of mouse embryonic stem cells in mitochondria.

BACKGROUND: The pluripotent state of embryonic stem (ES) cells is controlled by a network of specific transcription factors. Recent studies also suggested the significant contribution of mitochondria on the regulation of pluripotent stem cells. However, the molecules involved in these regulations are still unknown. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we found that prohibitin 2 (PHB2), a pleiotrophic factor mainly localized in mitochondria, is a crucial regulatory factor for the homeostasis and differentiation of ES cells. PHB2 was highly expressed in undifferentiated mouse ES cells, and the expression was decreased during the differentiation of ES cells. Knockdown of PHB2 induced significant apoptosis in pluripotent ES cells, whereas enhanced expression of PHB2 contributed to the proliferation of ES cells. However, enhanced expression of PHB2 strongly inhibited ES cell differentiation into neuronal and endodermal cells. Interestingly, only PHB2 with intact mitochondrial targeting signal showed these specific effects on ES cells. Moreover, overexpression of PHB2 enhanced the processing of a dynamin-like GTPase (OPA1) that regulates mitochondrial fusion and cristae remodeling, which could induce partial dysfunction of mitochondria. CONCLUSIONS/SIGNIFICANCE: Our results suggest that PHB2 is a crucial mitochondrial regulator for homeostasis and lineage-specific differentiation of ES cells

Prohibitin 2 (PHB2) is highly expressed in pluripotent mouse embryonic stem (ES) cells and mainly localized in mitochondria.

<p>(<b>A</b>) High expression of PHBs in pluripotent ES cells. ES cells cultured with or without LIF for 1 week were subjected to immunoblotting with the indicated antibodies. (<b>B</b>) Subcellular fractionation of ES cells cultured in the presence of leukemia inhibitory factor (LIF). The indicated proteins were detected by immunoblotting after separation by SDS-PAGE. (<b>C</b>) Localization of PHB2 in pluripotent ES cells. Pluripotent ES cells cultured in the presence of LIF were analyzed by confocal microscopy after immunofluorescence staining with a PHB2 antibody (green). Mitochondria and nuclear DNA were stained with MitoTracker (red) and DAPI (blue), respectively. Enlarged images of the boxed area in the left panels are shown in the middle and right panels. The white solid and dotted circles in the middle panels show the plasma membrane and nuclear envelopes of ES cells, respectively. Scale bar, 10 µm. (<b>D</b>) ES cells cultured with or without LIF for 1 week were analyzed by immunofluorescence staining with a PHB2 or Oct4 antibody. Scale bar, 30 µm.</p

Ultrastructural analysis of mitochondria in PHB2-overexpressing ES cells and PHB2-knockdown ES cells by electron microscopy.

<p>(<b>A</b>) Mouse ES cells (EBRTcH3) expressing with PHB2 shRNA. (<b>B</b>) ES cells (EBRTcH3) expressing a control shRNA. (<b>C</b>) Mouse D3 cells overexpressing PHB2. (<b>D</b>) D3 cells transfected with a control vector. Scale bar, 500 nm. (<b>E</b>) Semiquantitation of morphological differences of mitochondria in D3 cells stably expressing PHB2 or control vector. More than 100 mitochondria were analyzed in these cells. (<b>F</b>) Semiquantitation of morphological differences of mitochondria after neuronal differentiation of D3 cells stably expressing PHB2. The ES cells used in (E) were differentiated into the neuronal lineage by using the SFEB method for 9 days, and the samples on day 8 (d8) and day 9 (d9) were subjected to electron microscopy. More than 100 mitochondria were analyzed in these cells. (<b>G, H</b>) Immunoblotting of OPA1 in ES cells. Whole lysate of EBRTcH3 cells that express PHB2 shRNA (G) or D3 cells that express PHB2-Flag (H) were analyzed by immunoblotting with OPA1 antibody. α-Tubulin was used as a loading control.</p

PHB2 localized in mitochondria inhibits neuronal differentiation of ES cells.

<p>(<b>A–C</b>) Ectopic expression of PHB2^WT but not PHB2^AAAA inhibits neuronal differentiation. ES cells expressing PHB2-GFP were differentiated into neuronal cells as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081552#pone-0081552-g004" target="_blank">Fig. 4E</a>. (A) The differentiated cells were immunostained with either a Tuj1 or a Neurod1 antibody. Scale bar, 20 µm. (B) Tuj1-positive or (C) Neurod1-positive cells were counted in more than 5 different eye fields. (<b>D</b>) Endogenous PHBs do not shuttle in ES cells. Mouse ES cells were treated with a nuclear export inhibitor, LMB, at 10 ng/ml for 8 h. The nuclear-cytoplasm shuttling protein Smad4 was used as a positive control for LMB. Scale bar, 10 µm. Similar results were obtained by LMB treatment at 10 ng/ml for 1 h (data not shown).</p

ATP biosynthesis, ROS production, and mitochondrial membrane potential of PHB2-knockdown ES cells and PHB2-overexpressing ES cells.

<p>(<b>A, B</b>) ATP concentration (A) and ROS level (B) were measured with EBRTcH3 cells that express PHB2 shRNA under the control of a Tc promoter. The ES cells were cultured in either the absence or presence of Tet for 4 days. (<b>C</b>) Mitochondrial membrane potential in ES cells transiently transfected with PHB2 siRNA or control siRNA. The ES cells were cultured for 45 h, and treated with or without cyclosporin A (CsA). (<b>D–F</b>) ATP concentration (D), ROS level (E), and mitochondrial membrane potential (F) were measured in EBRTcH3 cells that express PHB2 under the control of Tc promoter in the presence of LIF. The ES cells were cultured either absence or presence of Tc for 3 days.</p

PHB2 localized in mitochondria is essential for the survival of pluripotent ES cells.

<p>(<b>A</b>) N-terminal sequence of the mitochondria-targeting signal mutated version of PHB2. (<b>B</b>) Establishment of shRNA-insensitive PHB2-GFP stable clones in mouse ES cells. The wild type and the mitochondria-targeted signal-mutated version of PHB2-expressing ES clones were established. The expression of these proteins was monitored by immunoblotting with a GFP antibody. (<b>C</b>) Subcellular localization of PHB2-GFP^WT and PHB2^AAAA-GFP proteins in pluripotent ES cells. Confocal images of GFP-tagged PHB2 in ES cells are shown. Arrowheads indicate the location of mitochondria in ES cells. PHB2^AAAA-GFP but not PHB2-GFP^WT failed to localize in mitochondria. Scale bar, 5 µm. (<b>D, E</b>) PHB2^WT but not PHB2^AAAA rescued cells from apoptosis induced by PHB2 knockdown in ES cells. ES cells expressing the PHB2^WT or PHB2^AAAA transgene (1×10⁴ cells) were infected with PHB2 shRNA- or the control shRNA-expressing retrovirus, and cultured in the presence of 500 µg/ml G418 for 10 days (D). The resulting numbers of colonies counted in 5 different eye fields are shown in (E). (<b>F, G</b>) TUNEL staining of PHB2-knockdown ES cells rescued by the exogenous mitochondrial PHB2 gene. ES cells expressing the control vector or shRNA-insensitive PHB2-GFP (1×10⁴ cells) were transfected with PHB2 shRNA vector and cultured for 3 days. The apoptotic cells were detected by TUNEL staining (F), and the numbers of cells were counted (G). Knockdown of endogenous PHB2 induced TUNEL-positive apoptosis. Cells were rescued from apoptosis by ectopic expression of PHB2^WT but not PHB2^AAAA.</p